Eccentric valve control



Dec. l, 1936.

H. A. CENTERVALL ECCENTRIC VALVE CONTROL Filed April 21,- 1935 @NNN WN, NQ

INVENTOR.

'f6' ATTORNEYS Patented Dec. 1, 1936 UNITED STTES 2,062,296V ECCENTRIC' VALVE CONTROL Hugo A. Centervall, Brooklyn, N. Y., assignor tok Manly Corporation, New York, N. Y., a corpora tion of New York Application April 21, 1933, Serial No. 667,148

7 Claims.

This invention relates to control mechanism for power devices operated by fluid under pressure and more particularly to control mechanisms for devices of this class which are adapted to perform such functions as braking and steering of a motor vehicle. I have accordingly chosen to illustrate the invention in connection with hydraulic power steering apparatus for a conventional automobile.

The principal object of the invention is to provde an improved mechanism of this class that is simple, compact and positive in action. Other and more specic objects will appear from the following description of an illustrative embodiment of the present invention shown in the accompanying drawing.

In the drawingzy Figure 1 is a side View, partly in section, showing a preferred embodiment of the invention as applied to steering apparatus for a conventional automobile.

Figure 2 is a view, partly in section, taken along the line 2-2 of Figure 1.

Figure 3 is a fragmentary side View, partly in section, showing a modification.

Before explaining the present invention, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts described herein and illus.- trated in the accompanying drawing, since the invention is capable of other embodiments and of being practised and carried out in other ways. lt

is also to be understood that the phraseologyor terminology used herein is for the purpose of description and not for limitation, and it is not intended to limit the invention beyond the terms of the several claims hereto appended as considered in view of the prior art and the requirements thereof.

Referring now to Figure 1 of the drawing, the steering gear casing I0 is appropriately supported, as by bolts II, upon the side member I2 of the frame of the motor vehicle. The steering shaft I3 is operatively connected with the steering arm |5 by means of mechanism, not shown, in the steering gear casing I0 and the steering arm cross shaft I4 which projects through a suitable opening in the side frame member I2 and to which the hub I6 on the upper end of said steering arm I5 is appropriately secured, as by the nut Il.- The steering shaft I3 is adapted to be rotated by the usual steering wheel, not shown, and the arrangement is such that counter-clockwise rotationof said steering shaft I3 causes the steering arm I5 to swing forwardly, or toward the left as viewed in Figure 1, and similarly clockwise rotation of said steering shaft I3 causes said steering arm I5 to swing rearwardly in the usual manner.

As shown in Fig. 2, the lower end of the steering arm I5 is formed with a hub I8 whose preferably tapered bore is adapted toreceive one end of a steering arm pin I9 which is held in place by an appropriate nut 20 on ythe threaded end of said pin I9 projecting through said bore. The steering arm pin I9 is received within a bore 22 positioned eccentrically in a cylindrical member 23, hereinafter termed the eccentric, which in turn iS received within the bore 24 formed in the cylinder body, broadly designated by the numeral 25. The parts are held in `position by the flange 2| formed onthek end of the steering arm pin |9 kand the arrangement issuch that the eccentric 23 is free tcturn about said steering arm pin |9 and is likewise free to turn in the bore 24. The amount of turning or rotation of the eccentric 23 in theV bore. 24 is limited by the pin 26 whose one end is secured in said eccentric 23 and whose other end is here shown as projecting downwardly into a suitable slot A2'I whose ends act as stopsfor said pin 26.

'The cylinder body 25 is here shown as of the movable typeand includes a cylinder 28 whose open end is closed by a suitable plug 29. Slidable within the cylinder 28 is a double acting piston 30 y attached to one end of a piston rod 3| which projects rearwardly through an appropriate opening in the plug 29, suitable packing 32 being used to prevent leakage. The rear or outer end of the piston rod 3| is pivotally attached, as at 33, to a bracket 34 depending from and supported by the side frame member I2. The cylinderbody 25 is thus supported by the steering arm pin I9 and the piston rod 3| and" is therefore movable lengthwise of said side frame member I2 and is free to rock to adjust itself to any angularity with respect to the steering arm I5 and other parts of the apparatus.r The piston 30 and the piston rod 3|, however, are held against Aany longitudinal movement with respect to the side frame member l2 but arelikewise free to rock upon the pivot 33 vto adjust for any angularity of the cylinder body 25. l l ;k

The cylinder bodyA 25is also shown as including ay cylindrical valve bore 35 which in lthis instance is positioned at substantially right angles to the bore ofthe cylinder 28. The valve borev 35 is provided with a port 36 formed by` its intersection with the passage 38 which, together with the passage 39, connects said valve bore withthe rear end of the` cylinder 28; similarly, .the valve bore is provided with a port 31 formed by its intersection with the passage 48 which connects said valve bore 35 with the forward end of the cylinder 28. The valve bore 35 is also provided with a high pressure inlet port 4| positioned intermediate of the ports 3B and 31 and with an exhaust port 42 located in the upper end of said valve bore 35. The high pressure inlet port 4| is suitably connected with one end of a exible tubing 43 which connects said port 4| with the source of pressure fluid, not shown, and similarly the exhaust port 42 is suitably connected to one end of a flexible tubing 44 which connects said port 42 with a reservoir, not shown. y

Within the valve bore 35 is a slidab-ly fitted control valve member 45 having three heads, 46, 41 and 48 respectively, which are separated by the reduced portions 49 and 50 respectively. In the present embodiment the proportions are such that when the control valve 45 is in its neutral position,` -as-shown in Figure 1,'the heads 46' and 41 cover the ports 36 and Y31` respectively while the high pressure inlet port 4| is` in communication with the reduced portion 49in all positions of adjustment of saidcontrol valve 45. The control valve 45 is also provided with a longitudinal passage 5|, indicated bythe dotted lines, which extends through 'said control valve 45v from its upper end to the reduced portion 50 where it connects with the radial passage 52.

The control valve 45 is adapted to be moved lengthwise within the valve bore 35 and is accordingly operatively connected with the eccentric 23. In the present instance the control valve 45 is provided with a stem 53 upon whose end is formed a flange 54 which engages a suitable notch 55 in the periphery of theeccen-tric 23. Clockwise rotation of the'eccentric 23, as viewed in Figure l, therefore moves the control valve 45 upwardly while counter-clockwise rotation of said eccentric 23 moves said control valve 45 downwardly. v Y l The connector 58'is here vshown as formed integrally with the cylinder body 25 and is attached by the usual ball and socket construction, indicated by the dotted lines at 59, to one end of the usual drag-link 60,Y here shown as broken olf. The drag-link 60 is presumed to be operatively connected'with avconventional front road wheel assembly of anautomobile in the usual manner, so that forward movement ofv said drag link 60 away from its neutral or straight ahead position,`as shown in Figure 1, moves said front road wheels so as to cause the vehicle to turn toward the left; while rearward movement of said drag link 6U away from its neutral position moves said front roadwheels so as to cause the vehicle to turn vtoward the right.

The operation of the device is as follows:

When the drivergwishes to steer the vehicle toward the left, he turns the steering shaft I3, by means of the steering wheel, in a counter-clockwise direction`which, through the intervening mechanism, causes the steering arm l5 to swing forwardly or to the left as viewed in Figure 1. To the steering arm pin I9' is thus imparted a force tending to move it forwardly with'respect to theicylinder Ybody 25, and thisforce, acting upon the eccentrically positioned bore 22, causes the eccentric 23 to turn in apcounter-clockwise direction in its bore 24 and consequently moves the control valve-45 downwardly in the valve bore 35j. f This turning of the eccentric 23 causes a very slight raising of the adjacent end of theV cylinder bod-y 25 but this is such a small amount as to be practically negligible and is readily permitted by the ball and socket connection with the drag link and the pivotal mounting 33 of the piston rod 3|. As the control valve 45 begins to move, however, the head 41 begins to uncover the port 31 and thus admits high pressure fluid from the tubing 43, the high pressure inlet port 4| and the reduced portion 49 into the forward end of the cylinder 28; at the same time, the head 46 begins to uncover the port 46 and thus connects the rear end of the cylinder 28 with the upper end of the valve bore 35, the exhaust port 42 and the tubing 44 so that excess fluid may pass out of the rear end of said cylinder 28 and return to the reservoir.

As the piston 30 is held against longitudinal movement, the pressure thus exerted by the high pressure fluid in the forward end of the cylinder 28 moves said cylinder 28, and hence the entire cylinder body 25 and the drag link 60, forwardly or toward the left'as viewed in Fig. l. Power is thus transmitted through the drag link to the front roadwheel assembly and causes said 4road wheels to move so as to turn the vehicle toward the left. This movement continues as long as the driver continues to turn the steering shaft i3 in a counter-clockwise direction.

As the cylinder body 25 moves forward, however, it obviously carries with it the eccentric 23 and as long as said eccentric 23 and the steering arm pin I9 move at the same speed and there is no relative movement between them, said eccentric 23 will not turn in its bore 24 and hence there will be no movement of the control valve 45. But whenever the speed of the eccentric 23 exceeds the speed of the steering arm pin I9, as when the driver turns the steering shaft 3 more slowly or ceases to turn it at all, the force exerted upon said eccentric 23 by the moving cylinder body 25 tends to swing said eccentric forwardly about the steering arm pin |'9 as a pivot and hence causes said eccentric 23 to turn in a clockwise direction in its bore 24. This clockwise rotation of the eccentric 23 moves the control valve .45 upwardly, thus tending to return it to its neutral position as shown in Figure 1. A follow-up action is thus set up so that when the driver stops turning the steering shaft |3, the control Yvalve 45 almost immediately closes the ports 35 and 31 thus cutting ofi admission of the high pressure liuid from thel forward end of the cylinder 28 and cutting off the exhaust of fluid from the rear end of said cylinder 28. The cylinder body 25 and its connected members are thus brought to rest.

To steer the vehicle toward the right, the driver turns the steering shaft I3 in a clockwise direction and the operation of the controls and of the cylinder 28 is obviously reversed. High pressure. fluid is now admitted to the rear end of the cylinder 28 and excess fluid is exhausted from the forward end of said cylinder 28,A passing through the port 3 1, the reduced portion 50,- the radial passage 52'the longitudinal passage 5|, the upper end of the valve bore 35 and out throughthe exhaust port 42 land the tubing"` to the reservoir. v

Steering isthus effected by power and it is necessary for the driver to expend only enough energy to move thecontrol members, and this is practically negligible. j

It will be evident fromv the foregoing that there is a correspondingr definite fore and aft position of the cylinder body 25- for every position of the steering arm pin Wand the device operates to `continuously maintain thisvcorresponding position. For purposes of illustration, let` us assume that the parts are' in the position-shown in Figure 1, that the steering arm pin |9 is stationary and that the cylinder body 25 is displaced, as because of leakage'from the cylinder r28 for example, toward the right. As this displacement of the cylinder body 25 commences, the eccentric 23 immediately begins to turn in a counter-clockwise direction in its bore 24 and with the'steering arm pin I9 as a pivot, thus moving the control valve 45 downwardly. The forward end of the cylinder 28 is thus almost Vimmediately connected with the high pressure inlet port 4| and the high pressure fluid almost instantaneously moves the cylinder body 25 toward the left and restores it to its proper position, the control valve 45 likewise being restored to its neutral position by the follow-up action already described. It is therefore impossible for the cylinder body 25 to be displaced any material distance away from its proper position andany displacement that may occur is almost instantaneously rectified.

If the source of high pressure fluid should fail or if the power apparatus should for any reason fail to respond, steering may be effected manually by the same movement of the same controls already described for power steering, though the driver must obviously exert more energy. In this case the operation of the steering arm pin I9, the eccentric 23 and the control valve 45 is initially the same as in power steering-but when the power apparatus fails to respond and to produce the follow-up action, the movement of these parts continues until the pin 26 strikes one end or the other of the slot 21. Further rotation of the eccentric 23 is thus prevented and manual power may be transmitted to the drag link 60.

The embodiment shown in Figure 3 differs from that already described principally in that the pin |26 not only serves to limit the rotation of the eccentric |23 but is also employed to actuate the control valve |45. In this instance the pin |26 projects forwardly from the eccentric |23, in which its one end is suitably secured, through the slot |21 which connects the bore |24 with the valve bore |35. The valve stem |53 is formed with a groove |54 which engages the forward end of the pin |26 and the arrangement is preferably such that said pin |26 is sub- A stantially at right angles to the control valve |45 when said control valve |45 is in its neutral position as shown in Figure 3. This construction makes it possible to employ a smaller eccentric than might otherwise be required to produce the desired movement of the control valve |45.

For ease in assembly, there is also provided a hole |6| drilled substantially in line with the slot |21 and connecting the valve bore |35 with the usual hollow end of the connector |58. Like- Wise, the slot |21 is preferably elongated lengthwise of the bore |24. In assembling, the eccentric |23 is rst inserted in the bore |24 and the pin |26 is inserted through the hole |6| and secured in the appropriate hole in said eccentric |23. The eccentric |23 is then moved lengthwise of the bore |24, as is made possible by the elongation of the slot |21, and the control valve |45 is inserted in the bore |35 through its open upper end. The eccentric |23 is then moved back into position in the bore |24 so that the groove |54 engages the pin |26.

While the control valves 45 and |45 have been herein shown and described as of the normally 'closed type which cuts off communication v-betvveen the cylinder and the valve bore when vthe control valve is in its neutral position, the in- -vention is not limited to the use Yof a control valve of this type. If preferred, for example, the control valve may be made of the normallyl open type by which both ends of the cylinder are -in communication with'the high pressure inlet' port when said control valve is in its neutral position, or other types of control valve lmaybefemployed. Likewise, the pin 26 and .the pi-'n` |26 may -be made integral with the yeccentric members, suitable modifications being made' mother parts to permit assembly etc., ora' key may lbe substituted for the pins and made to extendpart or all of the length of the eccentricy members in which appropriate key-waysare provided.

In both embodiments shown, .it willbe evident that the movement of the steering arm pin with respect to the cylinder body, orvice versa, produces a corresponding denite and positive movement of the control valve in one direction or the other and similarly that the reponse of the power apparatus produces a corresponding deinite and positive movement of said control valve in the vopposite direction. All movements of the control valve are thus positively actuated. It will also be evident that such movement of the valve actuating elements produces proportional but greater-movementyof the control v-alve and due to this multiplication of motion, the device may be made as sensitivev as desired and the control valve structure, maybe varied through wider limits than would otherwise be practical.

I claim:

1. In a device of the class described, a fluid motor comprising a relatively stationary piston member and a relatively movable cylinder body having a bore therein, a valve controlling the operation of said motor, said valve being movable with and movable with respect to said cylinder body, a cylindrical member rotatably mounted in said bore, a manually movable control member connected eccentrically with said cylindrical member, and an operative connection between said valve and said cylindrical member for movement of said valve simultaneously with the rotation of said cylindrical member.

2. In a device of the class described, a fluid motor comprising a relatively stationary piston member and a. relatively movable cylinder body having a bore therein, a valve controlling the operation of said motor, said Valve being movable with and movable with respect to said movable cylinder body, a cylindrical member rotatably mounted in said bore, stops limiting the rotation of said cylindrical member in said'bore, a manually movable control member connected eccentrically with said cylindrical member and an operative connection between said valve and said cylindrical member for movement of said valve simultaneously with the rotation of said cylindrical member.

3. In a device of the class described, a uid motor comprising a relatively stationary member and a relatively movable member, a part so connected as to be movable with said movable member and having a bore therein, a valve controlling the operation of said motor, said valve being movable with and movable with respect to said part, a cylindrical member rotatably mounted in said bore, a manually movable control member connected eccentrically with said cylindrical member, and an operative connection between said valve and saidcylindrical member for movement of said valve simultaneously with the rotation of said. cylindrical member. A

4. In a device of the class described a iluid motor comprising a relatively stationary and a relatively movable member, a part so connected as to be movable with said movable member and having a bore therein, a valve controlling the operation of said motor, said valve being movable with and movable with respect to said part, a cylindrical member rotatably mounted in said bore, stops limiting the rotation of said cylindrical member in said bore, a manually movable control member connected eccentrically with said cylindrical member, and an operative connection between said valve and said cylindrical member for movement of said valve simultaneously with the rotation of said cylindrical member.

5. In a device of the class described, a fluid motor comprising a relatively stationary member and a relatively movable member, a part so connected as to be movable with the movable member of said motor and having a bore therein, a longitudinally slidable valve carried by said part for controlling the operation of said motor, a cylindrical member rotatably mounted in said bore, a manually movable control member connected eccentrically with said cylindrical member, and an voperative connection between said longitudinallyk slidable valve and said cylindrical memberV for movement of said valve simultaneously with the rotation. of said cylindrical member.

' 6. In. a. device of the class described, a poweroperated mechanism comprising a relatively stationary memberand a relatively movable member, a part so connected as to be movable with said movable member and havingV an aperture therein, control means for said power operated mechanism, said control means being movable with and movable with respect to said part, an element mounted for rotative movement in said aperture, a manually movable control member connected within said aperture to said element to cause said element to rotate in said aperture and to transmit manual eiort tol said element, and an operative connection between said control means and said element for movement of said control means simultaneously with the rotation of said element.

'7. In a device of the class described, a poweroperated mechanism comprising a relatively stationary member and a relatively movable member, aA part soV connected as to be movable with said movable member and having a bore therein, control means for said power operated mechanism, said control means being movable with and movable withA respect to said part, a cylindrical member rotatably mounted in said bore, a manually movable control member eccentrically connected, with said cylindrical member, and an operative connection between said control means and said cylindrical member for movement of said control means simultaneously with the rotation of said cylindrical member.

Y HUGO A. CENTERVALL. 

